/**
 * Copyright (c) 2010 Yahoo! Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you
 * may not use this file except in compliance with the License. You
 * may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * permissions and limitations under the License. See accompanying
 * LICENSE file.
 */
package com.googlecode.concurrentlinkedhashmap.generator;

import java.util.Random;

/**
 * Generates integers randomly uniform from an interval.
 *
 * @author Brian Cooper
 * @see <a href="http://research.yahoo.com/Web_Information_Management/YCSB">YCSB</a>
 */
public class UniformIntegerGenerator extends IntegerGenerator {
  Random _random;
  int _lb, _ub, _interval;

  /**
   * Creates a generator that will return integers uniformly randomly from the
   * interval [lb,ub] inclusive (that is, lb and ub are possible values)
   *
   * @param lb the lower bound (inclusive) of generated values
   * @param ub the upper bound (inclusive) of generated values
   */
  public UniformIntegerGenerator(int lb, int ub) {
    _random = new Random();
    _lb = lb;
    _ub = ub;
    _interval = _ub - _lb + 1;
  }

  @Override
  public int nextInt() {
    int ret = _random.nextInt(_interval) + _lb;
    setLastInt(ret);

    return ret;
  }
}
